People see our chickens running around the farm yard and sometimes wonder why they don't all just fly away. Well, that's a good question. Most of today's breeds have been bred for their meat or egg laying ability and have lost their capability to be very strong fliers. Some breeds can fly for very short distances having no trouble getting out of the way of our sometimes rambunctious goats, for example, but they can't fly for any distance to speak of, like their ancestors could. You can find out more about this topic at The Straight Dope.